Motorcycle steering using compound leverage

ABSTRACT

A compound lever motorcycle steering mechanism comprised of an upper and lower lever parallel and adjacent to one another. With one lever being attached at a right angle to a shaft inside a collar or bearing to form a second axis adjacent to, and parallel with the axis where the front forks of the motorcycle are attached by another shaft to the main frame of the motorcycle. Said lever also having an attachment for a handlebar or set of handlebars, as well as a second shaft, pin, or bolt protruding at a right angle from the lever, and into a longitudinal slot, opening, or channel in the second lever, of a width only minimally larger than the diameter of said protruding shaft to sufficiently allow fore and aft movement of same through the slotted second shaft, which is rigidly attached or affixed to the front forks.

FIELD OF THE INVENTION

This invention is related to a means of steering a motorcycle, and more specifically a means of improving the prior art of existing motorcycles, using fork-mounted handlebars attached to the main frame of the motorcycle at a vertical axis, by adding a variable leverage advantage system requiring less physical effort from the rider to steer the motorcycle, while also reducing the necessary width of the handlebars.

BACKGROUND OF THE INVENTION

The existing art for the turning or steering of motorcycles has for the most part, changed very little since the advent of the first commercially available motorcycles nearly a century ago. Today, nearly all motorcycles still employ the same means of steering or turning as was first used not only on those early motorcycles, but also the common bicycle. In this common, or bicycle style of forks, the front wheel of the motorcycle is attached to the front forks by a horizontal axle, with the forks then attached to the main frame of the motorcycle by a more or less single vertical shaft, often surrounded by a bearing, forming a rotational axis which allows the front forks and front wheel to turn to the left or right, when the rider applies force by pushing or pulling on the handlebars also attached to the front forks or front fork assembly. For the most part, the method of mounting a handlebar or handlebars directly to the forks or fork assembly functions well enough. However, there is one characteristic to this method of steering the motorcycle that is disadvantageous. This characteristic is the total width necessary of the handlebar or handlebars, in order to provide the necessary leverage for the rider to easily turn the motorcycle front forks and wheel. The disadvantage of the handlebar width is that it tends to increase the amount of wind resistance the motorcycle encounters while traveling forward in two ways. First, the wider the handlebar or handlebars, the wider each of the rider's hands and arms are extended to each side, thus increasing the cross section of both the motorcycle and the rider that encounters wind resistance as the motorcycle travels forward. Second, on racing motorcycles, or sport bike type motorcycles equipped with aerodynamic fairings attached to the main frame of the motorcycle, the width of existing handlebars require that spaces, cutouts, or openings be located in the sides of the fairing adjacent to the handlebar or handlebars, to allow clearance for the width of the handlebar as they are turned to one side or the other. These openings in the fairing necessitated by the width of the handlebar result in the interruption of the aerodynamic surface of the fairing, therefore resulting in a cessation of laminar or smooth airflow over the fairing surface, and thus increase wind resistance and aerodynamic drag. Therefore, the speed, acceleration, and fuel efficiency of the motorcycle are decreased. The subject device of this patent application substantially overcomes these aerodynamic drag inefficiencies while providing a means of adequate leverage for the rider to turn the motorcycle easily and safely. Although there are a few other existing prior art variations to the means of steering a motorcycle other than the common, or bicycle style handlebars and forks as described above, the subject device is not intended to be applied, implemented or used with those variations. Rather, as the common, or bicycle style forks are nearly universal in use and popularity for motorcycles, the subject device of this application is intended as an improvement to the common existing art as found therein.

OBJECT OF THE INVENTION

The steering system, also known as the device hereinafter described improves the prior art of common handlebar steering of motorcycles in several ways. First, by use of much more narrow handlebars, the cross section of the motorcycle and rider that is exposed to any oncoming airflow is reduced, diminishing wind resistance. Second, such narrower handlebars allow the handlebar, and a substantial portion of the rider's hands and arms to be completely shielded from oncoming wind, within a fairing or airfoil unbroken by the openings, gaps, or spaces required in the prior art of existing faired racing motorcycles, and sport bikes. This narrower handlebar width of the device, still provides adequate leverage for the rider to easily turn and control the motorcycle. This is accomplished by use of an additional, more or less vertical axis in addition to the axis on which the front forks turn at the intersection of the steering stem and headstock, in conjunction with a system of elongated members, also known as levers which a provide a leverage advantage allowing the motorcycle handlebar and front wheel to be turned easily, and fully to the left or right. Therefore, the device is superior to the existing prior art as it will allow the motorcycle to offer a higher top speed and increased fuel mileage, while retaining or even increasing the ease of turning the handlebar to the left or right. Further objects and advantages will become apparent from a consideration of the drawings and description to follow.

BRIEF SUMMARY OF THE INVENTION

Briefly, the device consists of a steering system for a motorcycle equipped with common motorcycle, or bicycle type front forks. The device allows the use of a much narrower handlebar or set of handlebars, by the addition of a second, more or less vertical axis rotatably coupled to the frame of the motorcycle, which is in addition to the steering stem axis located in the headstock of the motorcycle frame which serves to rotatably couple the front forks and wheel to the main frame of the motorcycle. Two more or less horizontal and parallel elongated members or levers are slidably engaged through a fixedly coupled pin to one of the other. With an upper lever rotatably attached near one of its ends to the more or less vertical axis of the device, and to the actual handlebar or handlebars near the opposite end of the lever. A lower and parallel lever is rigidly attached directly to the front forks, at its rear-most portion, with the forward portion of the lever forming a channel, groove or opening through which a pin is fixedly coupled to the upper lever at a right angle may pass, and come into contact with the lower lever, slidably engaging the two levers.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is the steering system is shown in relation to a motorcycle from a side perspective. In this figure, some of the components of the device are identified by number as follows: Number 1 is a portion containing an axis of rotation for the upper lever; number 4 is the upper lever; number 3 identifies the lower lever; number 5 identifies a pin fixedly coupled to the upper lever; number 6 is the handlebar clamp; number 7 is the handlebar; number 8 is the right fork; number 9 is a portion of the main frame of the motorcycle; and number 2 identifies the crown nut of the steering stem,, and the headstock of the motorcycle.

FIGS. 2-5 show the steering system from a top perspective with the device shown respectively in a straight forward position; with the bottom lever, number 4 being shown as a single integral member which also forms the lower portion of the triple clamp of the front forks. In FIG. 2, the steering system is shown in a position indicating straight forward travel of the motorcycle, while FIG. 4 shows the position of the steering system in a left turn configuration, and FIG. 5 shows the position of the steering system in a right turn configuration. Shown variously in FIGS. 2, 4, and 5, are parts of the device numbered as follows: number 1 is a bearing holder which forms an axis or rotation for a shaft attached to number 4 the upper lever; number 2 is a crown nut attached to the top of the steering stem which rotates within the headstock of the motorcycle frame; number 3 is the lower lever of the steering device, in which number 12, an opening or raceway in the lower lever, allows number 5, a pin or bolt, fixedly coupled to item 4 the upper lever to slidably engage the two levers. Number 6 is the clamp attaching the handlebars, number 7, to the upper lever, number 4. Number 8 identifies either one or both of the fork tubes; number 9 denotes the frame of the motorcycle; number 10 is the shaft affixed to one end of the upper lever, number 4, which rotates laterally in bearings located in the bearing holder, number 1. Number 11 and 13, respectively note a threaded nut and washer which hold the shaft depicted as number 10, in position.

FIG. 6 is the position of the steering system is the same as in FIG. 2, and in addition, the steering device parts are also numbered the same, except with the addition of number 14, two bolts holding the forward portion of the lower lever to the front of the lower triple clamp, which together comprise the entire lever. Thus differing from FIG. 2, only in that the lower lever, number 3 was shown as integral with the lower triple clamp.

FIG. 7 is this figure shows a bottom view of the steering system, with the device in a position for straight forward travel. From this perspective the lower lever, number 3, is shown as a bolt on to the lower triple clamp, number 18, as shown in FIG. 6. Number 14 identifies the bolts holding the lower lever to the front of the lower triple clamp, number 18. Number 12 shows the opening or raceway in the lower lever, number 3. Number 5, identifies the pin or bolt attached to number 4, the upper lever; and number 15 is the nut holding number 5 in position. Number 8 again identifies a fork; and number 7, the handlebar.

FIGS. 3 and 8, the device is shown in a cutaway view from a side perspective. The numbered items in FIG. 3, are shown as follows: number 1 is the bearing box holder; number 2, the crown nut capping the steering stem which passes through the headstock of the frame of the motorcycle; number 3 is the lower lever; number 4, the upper lever; number 5, the pin or bolt affixed to the upper lever; number 6, the handlebar clamp; number 7, the handlebar; number 8, a fork tube; number 9, the frame of the motorcycle; number 10, the vertical shaft attached to the upper lever; number 11, the threaded nut holding the shaft in place; number 12, the opening or raceway in lower lever; number 17, the top triple clamp; number 18, the rear portion of the lower lever shown as an integral member. Number 21 shows top and bottom bearings surrounding the shaft of the top lever; number 22 is a spacer separating the top lever from the bottom of the bearing box and number 23 shows a cross section of the handlebar where it passes through the handlebar clamp.

FIG. 8 is identical to FIG. 3, except that the lower lever, number 3, is not shown as being an integral member as in FIG. 3, but rather as two parts coming together to form the lower lever, and consisting of a bolt-on lower lever, with the rear of same, number 20, affixed to the front of the lower triple clamp, number 19 of FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

As will be discussed in greater detail herein, disclosed herein can be for the purpose of explaining and understanding the invention reference will be made to the implementation as illustrated in FIGS. 1-8, but unless otherwise specified all descriptive references will primarily be made upon FIG. 3. It should also be understood that no limitation of the scope of the device is hereby intended by these drawings of the implementation in regard to the principles of the device, as other alternative implementations not shown in said figures are possible.

Beginning with FIG. 2 the device is shown from a top perspective, with the handlebars and front forks, in a center position, as they would be for the motorcycle to travel forward in a straight line. The principal parts or elements of the device are identified by numbers on the drawing. The item identified as number 1, is an axis of the device, and is constructed of a steel bearing holder made of steel or other hard material bar or tubing, cut, formed, and welded to form a structure, with circular openings, collars, or sleeves located at the top and bottom of the structure, to accommodate an upper and lower bearings that are positioned parallel to, and directly above and below each other, to accommodate a mostly vertical, steel or other hard material shaft through the inside diameter opening in each bearing. The top and bottom sides of both respective bearings noted above being flush with the top and bottom edges of the bearing holder. With the bearing holder positioned directly in front of, and parallel to the main axis contained in the headstock of the motorcycle frame, a saddle, or semicircular collar connected to the left and right sides of the bearing holder, extend directly rearward, and parallel with one another past the headstock of the main frame of the motorcycle. Those side portions of the bearing holder, number 1, extending rearward by the main headstock may be welded directly to the surface of the headstock, to provide an attachment point for the bearing holder, or alternatively, extended further to the rear and parallel with one another to attach directly to the frame tubes of the motorcycle by either welding, or by drilled holes with threaded screws or bolts inserted and corresponding threaded nuts.

Number 4, forms the upper lever of the invention and is made by cutting a portion of steel or other rigid material bar or tubing. A circular hole is then drilled at or near the center of one end portion of the lever, and a second circular hole is then drilled at or near the center of the opposite end portion of the lever. A shaft with threads at one end, and of sufficient length to pass vertically through both bearings and a bushing described below, with the threaded end exposed sufficient for a locking device, is then inserted through this second hole. Care should be taken to insure that the shaft and bar or tubing form a right angle to one another. The shaft is inserted to a point where the unthreaded end point is exactly flush with the bottom edge of the bar or tubing former the upper lever, at which point both items should be rigidly, and securely welded together. Two bearings of an outside diameter correspondent with the collar openings of the bearing holder, should be fitted to the vertical shaft portion of the upper lever, number 4. A bushing of a diameter to closely fit without binding, the vertical shaft, is then placed over the threaded end portion of the shaft and slid down the shaft until it comes into contact with the bar or tubing portion of the top of number 1. The treaded end of the shaft can then be inserted up through the center openings of both bearings of the bearing box, until the bushing on the shaft comes into contact with the inner race of the lower bearing. At that point, a flat washer of a diameter correspondent to the shaft, and a threaded nut of the same diameter as the threaded portion of the shaft, can be affixed to the threaded end of the shaft, and tightened to a point where the washer is in direct contact with the upper bearing, but not tightened to a point that impedes the free rotation of the bearing. For the purpose of safety a locking nut, or a combination of crenellated nut and drilled bisecting shaft hole and cotter key could be used to prevent the loosening or loss of the upper lever assembly.

At the hole near the forward end portion of the upper lever that a threaded shaft or bolt of one half inch diameter, is inserted downward through said hole. A bushing or spacer of the same diameter is then inserted upward over the downward end of the shaft or bolt, until it comes into contact with the bottom side of bar or tubing forming the upper lever. A bearing of the same inside diameter is then inserted upward over the downward end of the shaft or bolt, until it comes into direct contact with the previously installed bushing. Finally a threaded locking, or lockable nut is attached to secure the bearing snuggly, but again not to a tightness to prevent easy and free rotation of the bearing. To complete the upper lever that comprises item number 3, a set of two parallel steel or hard and rigid material clamps, with upper and lower portions, and with each of those portions having a semi-circular opening or cutout that together form a circular opening of a diameter to accommodate a handlebar, and that can be compressed down to rigidly and tightly secure the handlebar by the tightening of two threaded bolts or screws connecting the respective upper and lower halves of each clamp together. The clamps are then attached rigidly to the most frontal portion of the upper lever by welding. With the top portions of the clamps removed, a handlebar is inserted in the open clamp, with the top of each clamp then being replaced and the threaded screws or bolts in each clamp tightened to secure the handlebar.

Item number 3 represents the second lever which is either integral to the lower triple clamp of the front forks of the motorcycle or attached directly to and rigidly across the lower triple clamp of the front of the front forks of the motorcycle. This second lever is again constructed using steel or other rigid material bar or tubing in the following manner. A portion of bar or tubing is cut to a length correspondent to the width of the lower triple clamp, or front fork width. Two addition portions of the same or similar material are then cut to a length of slightly more than that of the upper lever, number 4. Each of these two additional portions are then affixed at a right angle to the first portion of bar or tubing correspondent in width to the lower triple clamp or front forks. The two portions of the same length are then placed upon the portion of bar or tubing correspondent to the width of the lower triple clamp, to form a right angle, and with the two portions being parallel to one another and separated by the distance of the outside diameter of the bearing attached to the forward shaft or bolt near the forward end portion of the upper lever. The two parallel shorter portions should then be carefully welded in place to form an open and parallel groove, channel, or raceway. At a corresponding and parallel point near the forward-most portion of both of these portions, a circular hole is drilled at a right angle through each portion. A threaded bolt sufficient in length to expose its threaded end through the outside edge of the second portion, through which it is inserted, is then inserted through said holes in each portion, and a locking nut secured by threading on the end of same. This shaft or bolt, and nut combination will later be used for adjusting the exact distance between both parallel pieces which together form an opening, or raceway, I in which the bearing attached to the pin, identified as number 5 extending downward from the frontal end of the upper lever identified as number 4.

At a point on the frontal side of the front forks located directly below the upper installed lever as identified as number 4, the second lower lever, number 3 is attached directly to the front of the lower triple clamp of the front fork assembly. The lower lever is attached by drilling to holes near the outside edge portion from each end of the bar or tubing forming the base portion of the lower lever that fits across the front forks. The entire lower lever assembly is then positioned flush with the frontal surface of the lower triple clamp, and parallel to the upper lever. When the correct alignment has been achieved the locations upon the triple clamp correspondent to the drilled holes in the base of the lower lever, are marked for drilling. Said holes are then drilled at right angles, and a threaded tap is then used to cut threads to a depth sufficient for bolts or screws to secure the lower lever. The lower lever is then attached by inserting and tightening two threaded bolts or screws. Care should be taken during final positioning the upper lever to insure that the bearing protruding downward on a shaft from the upper lever is placed inside of the channel or opening of the lower lever. Finally, the tightening bolt bisecting both sides of each parallel piece of the lower lever should be adjusted to a point where any excess slack between the outside race of the bearing protruding downward from the upper lever, and the insides of each of parallel piece of the upper lever is removed, but not to a point which restricts said bearing from moving freely, forward or backward in the opening or raceway formed by each side of the lower lever.

Accordingly, the invention is not limited except as by the appended claims. 

1. A motorcycle comprising: a frame; a wheel rotatably attached to the frame; a handlebar; rotatably attached to the frame; and a steering system including a first elongated member coupled to the handlebar, the elongated member rotatably coupled to the frame along a first axis of rotation and a second elongated member rotatably coupled to the frame along a second axis of rotation, the second elongated member coupled to the wheel, the second elongated member slidably engaged with the first elongated member.
 2. The motorcycle of claim 1 wherein the first elongated member is shorter than the second elongated member.
 3. The motorcycle of claim 1 wherein the first elongated member includes a steering stem rotatably coupled within a headstock, the headstock coupled to the frame.
 4. The motorcycle of claim 1 wherein the first elongated member is slidably engaged with the second elongated member through a pin fixedly coupled with the first elongated member and a bearing slidably coupled to the second elongated member, the pin fixedly coupled to the bearing.
 5. The motorcycle of claim 4 wherein the pin is fixedly coupled to the first elongated member a distance from the first axis of rotation and the bearing is slidably coupled to the second elongated member at least a second distance from the second axis of rotation, the first distance being smaller then the second distance.
 6. The motorcycle of claim 1 wherein the first elongated member extends from the frame in a first plane and the second elongated member extends from the frame in a second plane, the second plane being parallel to the first plane.
 7. The motorcycle of claim 1 wherein the second elongated member is coupled to the wheel through a first fork and a second fork.
 8. A steering system for a motorcycle, the motorcycle including a wheel, a frame, and a handlebar, the system comprising: a first elongated member coupled to the handlebar, the first elongated member rotatably coupled to the frame along a first axis of rotation and a second elongated member rotatably coupled to the frame along a second axis of rotation, the second elongated member coupled to the wheel, the second elongated member slidably engaged with the first elongated member.
 9. (canceled)
 10. The steering system of claim 8 wherein the first elongated member is shorter than the second elongated member.
 11. The steering system of claim 8 wherein the first elongated member includes a steering stem rotatably coupled within a headstock, the headstock coupled to the frame.
 12. The steering system of claim 8 wherein the second elongated member includes a steering stem rotatably coupled within a headstock, the headstock coupled to the frame.
 13. The steering system of claim 8 wherein the first elongated member is slidably engaged with the second elongated member through a pin fixedly coupled with the first elongated member and a bearing slidably coupled to the second elongated member, the pin fixedly coupled to the bearing.
 14. The steering system of claim 13 wherein pin is fixedly coupled to the first elongated member a first distance from the first axis of rotation and the bearing is slidably coupled to the second elongated member at least a second distance from the second axis of rotation, the first distance being smaller than the second distance.
 15. The steering system of claim 8 wherein the first elongated member extends from the frame in a first plane and the second elongated member extends from the frame in a second plane, the second plane being parallel to the first plane.
 16. The steering system of claim 8 wherein the second elongated member is coupled to the wheel through a first fork and a second fork.
 17. A method of steering a motorcycle, the motorcycle including a wheel, a frame, and a handlebar, the wheel rotatably coupled to the frame, the method comprising: coupling handlebar to a first elongated member rotatably coupled to the frame along a first axis of rotation; coupling the wheel to a second elongated member rotatably coupled to the frame along a second axis of rotation; receiving a force imparted upon the handlebar to provide a first rotational force to cause a first rotation of a first elongated member along the first axis of rotation; and transferring the first rotational force to a second elongated member to cause a second rotation of the second elongated member along a second axis of rotation thereby turning the wheel. 